I recently upgraded my PC from Ryzen 9 5900X DDR4 to Ryzen 9 9900X DDR5, GPU is the same RTX3070. And I noticed that encoding videos now takes much longer, compared to my previous hardware. I also noticed, that during the encoding CPU usage by Shotcut is only 30-35%. I both cases I used the same encoding settings. For example, encoding a simple 55 seconds 1218x2160 video project takes longer than 30 minutes (x264, dual pass, parallel processing is ON ) - which makes no sense. For example, when I use Avidemux to encode the same video with the same encoding settings and even with preset=veryslow, it only takes about 5-6 minutes and CPU usage is about 80%. I’m not using hardware encoding because I want a better quality video.
I tried Shotcut v25.05.11 on my Manjaro Linux, both installed from Manjaro repository and from flatpak. I also tried Windows version - and results are the same.
What can I do to make Shotcut use more than 30-35% of my CPU?
I’ve been using Shotcut for a long time and I really like it and I don’t want to switch to another editing software. Please, help!
That is very strange, but we have no idea what you are doing. For example, is “compared” using the exact same project and actually measured? In any case, I will give you the benefit of the doubt that 30+ minutes for 55 seconds is wrong… unless you applied some ridiculous heavy filter. Make a simple test:
start Shotcut
Settings > Video Mode > Automatic
open a short video that is at least 30 seconds long into the Source player but do not add it to Playlist or Timeline
in Export > Video turn OFF Parallel processing (That can only benefit image processing, which we are not going to do.)
Export File
How long did it take? Wait for it to finish; do not report an estimated remaining time.
I did the above test with a 47 second 4K60 video, and it took 2:20 minutes:seconds on my 12 core AMD Ryzen 5 5600G with the Shotcut 25.07 AppImage (without hardware encoder).
My main complaint is that the CPU usage is only 30-35%. I check and tried a lot of advises from the Internet, how to improve the CPU usage, but those were pretty old and none of the things I tried changed anything. I tried many combinations of Parallel processing on/off and different threads numbers and nothing helped to increase the CPU usage. Why does it only use 30-35% of CPU? That’s the problem.
Because there is a bottleneck somewhere (there is not intentional sleeping somewhere). In my test scenario above it uses close to 100% CPU. In your original post you wrote “video project.” That encompasses an infinite amount of possibilities, and not everything is optimal. If you willing to run that simple test, I will not help anymore.
I did the test. I took 30 seconds 4K video, I did the export without changing any settings (Parallel processing was OFF) and it rendered it in 28 seconds. CPU usage was about 73%.